Phenylalanine and Mental Retardation (PKU)

  • William L. Nyhan
Part of the Readings from the Encyclopedia of Neuroscience book series (REN)


Phenylketonuria (PKU) is the most important and most frequent disorder of aromatic amino acid metabolism. It results from a defect in phenylalanine hydroxylase, the enzyme that normally converts phenylalanine to tyrosine. The disorder was discovered some 50 years ago by Föiling who observed a deep green color on the addition of ferric chloride to the urine of two mentally retarded siblings and characterized the compound responsible as phenylpyruvic acid, the phenylketone for which the disorder has been named.


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Further reading

  1. Föiling, A (1934): Uber ausscheidung von Phenylbrenztraubensaure in den Harn als Stoffwechselanomalie in Verbindung mit Imbezillität. Hoppe-Seyler’s Z Physiol Chem 227: 169CrossRefGoogle Scholar
  2. Kaufman S, Berlow S, Sumer GK, et al (1978): Hyperphenylalaninemia due to a deficiency of biopterin. New Engl J Med 299: 673CrossRefGoogle Scholar
  3. Kaufman S, Holtzman NA, Milstien, S, Butler, IJ, Krumholz, A (1975): Phenylketonuria due to a deficiency of dihydropteridine reductase. New Engl J Med 293: 785CrossRefGoogle Scholar
  4. Nyhan WL (1984): Phenylketonuria. In: Abnormalities in Amino Acid Metabolism in Clinical Medicine. Norwalk, Conn: Appleton-Century-Crofts, pp 129–148Google Scholar
  5. Nyhan WL, Sakati NO (1976): Phenylketonuria (PKU). In: Genetic and Malformation Syndromes in Clinical Medicine. Chicago: Yearbook Medical Publishers, pp 6–9Google Scholar
  6. Woo SLC, Lidsky A, Chandra T, et al (1983): Prenatal diagnosis and carrier detection of classical phenylketonuria by cloning and characterization of the human phenylalanine hydroxylase gene. Clin Res 31: 479AGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1989

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  • William L. Nyhan

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